Since the inception of seafaring, humans have endeavored to attach various items to the transoms of watercraft hulls to help determine conditions both above and below the water's surface. In the last half of the twentieth century, popularity of pleasure watercraft has risen sharply. Many users of such watercraft, just as mariners of old, need assistance with navigation, operation, and locating marine quarry such as fish and wrecks.
Paralleling the rise in numbers of pleasure watercraft, sensor (transducer) technology has also increased throughout the last few decades. Transducers have been produced that are far more compact, rugged, less costly, and precise then their predecessors. Such improvements have enabled the boat-building industry to employ various transducers to expand navigational and operational capabilities for new watercraft, thus creating a level of sophistication in watercraft that has never been seen before. The ever-present desire to navigate and operate watercraft more safely, along with the desire to find various types of marine quarry, has pushed users of pleasure watercraft to retrofit their existing craft with the newly available marine transducers. While the transom of a watercraft hull is often a convenient place to locate such sensors, few resources have been devoted to develop ways in which to attach marine transducers to transoms.
Marine environments are very harsh on watercraft and accessories. Transducers attached below the waterline must withstand water pressure and current when the craft is underway, as well as resist the effects of water chemistry, fouling from marine life, and impacts from obstacles in the water such as submerged logs and buoys. Transducers attached to the transom of a watercraft hull must also resist impacts from trailering, docking, and storage. Since watercraft, especially boats, are operated in all types of climates, a marine transducer and its attachment device must also withstand a variety of temperatures.
Several devices have been developed to mount a transducer to the transom of a boat hull—the most basic of these is a screwed-on bracket. In this device, a mounting bracket is screwed to the transom. This device requires a sealant between the transom and the bracket that is always susceptible to leakage, which can lead to hull and transom damage that is very costly to repair. It also requires the installer to drill holes, which adds complexity to the installation process. This device has various forms, from a stamped stainless steel clamp, to a polyethylene “mother” board, which attaches to the transom and has space where an installer can place several transducer brackets; while such improvements may reduce the overall number of holes one must drill in the transom, this family of devices still requires at least one hole in the transom to mount the “mother” board.
Another mounting device uses a stainless-steel clamp that wraps around the submerged portion of a trolling motor. U.S. Pat. No. 6,490,229, issued to Caver describes such a device. This arrangement limits the operation of the transducer to the low speeds where the trolling motor is operating, and it creates the potential for interference between the motor and the transducer.
Yet another mounting device hangs over the transom and hooks to the lip of the gunwale. U.S. Pat. No. 5,529,272 issued to Baublitz, Sr. describes such a device. The arrangement is cumbersome and may interfere with other transom-mounted devices such as outboard engines, trolling motors, and trim tabs.
Another mounting device uses the drain hole that is generally located in the transom to mount the transducers. U.S. Pat. No. 4,811,310 issued to Willie describes such a device. The device uses a jamb nut with a washer and an o-ring as a seal. The disadvantage with this invention is that it prevents the owner from using the drain hole without removing the transducer. Furthermore, the number of transducers is proximately limited to the number of drain holes.
Since current transducer mounting systems have various features that make them marginally effective, the need exists for an improved mounting system to attach a marine transducer to the transom of a boat hull that results in minimal intrusion into the transom, is strong enough to withstand marine environments, and uses a minimum number of parts.